WO2018133711A1

WO2018133711A1 - Pier foundation and construction method therefor

Info

Publication number: WO2018133711A1
Application number: PCT/CN2018/071980
Authority: WO
Inventors: 王燏斌
Original assignee: 王燏斌
Priority date: 2017-01-18
Filing date: 2018-01-09
Publication date: 2018-07-26
Also published as: CN106759418A

Abstract

Provided is a pier foundation. The bottom of a pier foundation (1) is provided with a track (1-1) for a chain excavating apparatus (2) to operate, the chain excavating apparatus (2) mainly being composed of a chain cutter (3) and a transmission apparatus, the chain cutter (3) being composed of a chain (3-1) and a cutter (3-2) fixed on the chain (3-1), and the transmission apparatus mainly being composed of a sprocket (6) and a driving apparatus (4). The driving apparatus (4) drives the chain cutter (3), the chain cutter (3) runs along the track (1-1), the chain excavating apparatus (2) at the bottom of the pier foundation (1) excavates rock and soil, the chain cutter (3) operating perpendicularly upwards delivers excavated rock and soil above, and the chain cutter (3) at the bottom of the pier foundation (1) and the pier foundation (1) descend together. Further provided is a construction method for the pier foundation. The pier foundation (1) itself has the chain excavating apparatus (2) so whole on-site excavation is not needed, the pier foundation can be pre-formed at the work site or can be constructed by pouring while descending in on-site fixed formwork, the construction is simple, and costs are low.

Description

Bridge pier foundation and construction method thereof

Technical field

The invention relates to a bridge pier foundation and a construction method thereof, and belongs to the technical field of bridge engineering foundation construction.

Background technique

The existing pier foundation technology generally adopts the construction method of first cofferdam and then excavation, with long construction period, high labor intensity and poor working environment safety.

The existing foundation technology of the sinking well is based on excavation in the well and relies on its own gravity to overcome the frictional resistance of the well wall and sink to the design elevation to seal the bottom. The main defects are: long construction period, high cost, difficult to correct, and encountered well When an obstacle such as a bottom stone is used, the blade foot is difficult to overcome and is prone to suddenness and is prone to accidents.

Summary of the invention

The present invention proposes a pier foundation and a construction method thereof, the purpose of which is to overcome the drawbacks of the prior art.

The main advantages are as follows: 1) The pier foundation 1 can be manufactured in whole or in sections in the prefabrication field, or it can be lowered while pouring in the fixed formwork on site, and the construction is convenient; 2) the structure is simple; 3) the whole sinks on the site, The construction period is short and the cost is low.

For example, if it is applied in the field of sinking wells, its main advantages are as follows: 1) The sinking foundation is manufactured in the prefabricated section, and it can also be lowered in the fixed formwork on the site, the construction is simple and good quality; 2) the whole sinking at the site, The construction period is short and the cost is low; 3) It is especially suitable for the construction of obstacles such as boulder in the bottom of the well.

The technical solution of the invention is that the bottom of the foundation of the pier is provided with a chain knife running track, and a chain cutter for excavating rock and earth is installed on the track during construction, the chain knife is composed of a chain and a cutter fixed on the chain; the chain excavating device is mainly It consists of a chain cutter and a transmission device. The transmission device is mainly composed of a sprocket and a driving device. The driving device drives the chain cutter. The chain cutter runs along the track. The cutter at the bottom of the pier foundation excavates the rock and soil, and the chain cutter running vertically upwards will The excavated rock and soil is sent to the top, and the chain cutter and the pier foundation at the bottom of the pier foundation are lowered together.

The prefabrication method is divided into the following steps:

1) Blocking or integral prefabricated pier foundations at the workshop;

2) transport to the site to assemble the foundation of the pier and clamp it, and install the chain knife on the track at the bottom;

3) Install a chain drive and other devices to connect the chain with the cutter installed;

4) drive the chain, the chain knife excavates the rock at the bottom of the foundation of the pier, and the chain cutter that runs vertically upwards is brought to the top, and the base chain and the pier foundation at the bottom are lowered;

5) Grout after falling to the design depth, or remove the chain knife and then grout.

The cast-in method is divided into the following steps:

1) Clean up the site and build an operating platform;

2) Assembling the bottom of the foundation of the pier and installing a chain knife on the track at the bottom;

3) Assembling the intermediate frame, the upper frame and the pouring formwork;

4) Install the chain drive device and the tensioning device, and connect the chain cutters at the bottom of the pier foundation, the intermediate frame and the upper frame to form a chain excavation device;

5) Making a steel cage and pouring concrete in the formwork;

6) Drive the chain, the chain drives the tool to run along the track, the chain knife at the bottom of the pier foundation excavates the rock and soil, and the chain knife that runs vertically upwards transports the excavated rock and soil to the upper part, and the pier foundation decreases accordingly;

7) As the bottom of the foundation of the pier is lowered, the foundation of the pier in the formwork is lowered while pouring;

8) Drop to the design depth After the chain cutter is removed, the grout is removed and the pouring formwork is removed.

The invention has the advantages that the defects of the prior art are overcome, and since the pier foundation itself has a chain excavating device, the overall excavation of the site can be used to prefabricate the pier foundation in the workshop, or the side can be poured in the fixed template on the site. The construction is simple, especially the overall waterproofing is particularly good, the construction period is short, and the cost is low.

DRAWINGS

1 is a schematic structural view of a pier foundation 1 and a structural schematic view of the chain excavation device 2 when excavating the rock at the bottom of the pier foundation, and also the bottom track of the pier foundation 1 has a height difference, which facilitates the operation of the chain cutter 3 at the intersection. Schematic;

Figure 2 is a view in the direction of arrow A of Figure 1, and is also a schematic structural view of the driving device 4, the tensioning device 5 and the sprocket 6 constituting the chain excavating device 2;

Figure 3 is a cross-sectional view taken along line B-B of Figure 1, and is a schematic view showing the structure of the chain cutter 3 excavating the rock and soil horizontal conveyor 7-1 at the bottom of the pier foundation;

Figure 4 is a cross-sectional view taken along line C-C of Figure 1, and is also a schematic structural view of a vertical geotechnical conveyor 7-2 composed of a chain cutter 3 and a side cover 1-3;

5 is a schematic structural view of the chain cutter 3, and (a) is a schematic structural view of the chain 3-1 and the cutter 3-2, and is also composed of A ten-byte 3-1-1 and B ten-byte 3-1-2. Schematic diagram of the ten-byte structure of the chain 3-1; also a schematic diagram of the structure in which the chain 3-1 realizes space bending. (b) is a schematic structural view of the chain cutter composed of the rope 3-1B and the cutter 3-2B; also a schematic structural view of the rope 3-1B and the cutter 3-2B;

Figure 6 is a schematic view showing the construction of the foundation of the pier foundation 1;

7 is a schematic view of the B-method construction of the pier foundation 1, and is also a schematic structural view of the bottom rail B-1 and the pouring formwork B-4, and is also a structural schematic view of the upper frame B-3 being fixed on the working platform without lifting;

Figure 8 is a plan view of the A1 type pier foundation 8-1, the lower part of the ground is indicated by a broken line, and the chain cutter 3 can replace the tool 3-2 on the chain on the working platform to adapt to different geological conditions of different depths;

Figure 9 is a view taken along the line A in Figure 8;

Figure 10 is a B-B view of Figure 9, and is also a schematic structural view of the above part of the A1 type pier foundation 8-1;

Figure 11 is a C-C view of Figure 9, and is also a schematic structural view of the underside of the A1 type pier foundation 8-1;

Figure 12 is a plan view of the A2 type pier foundation 8-2, the lower part of which is indicated by a broken line;

Figure 13 is a view taken along line A of Figure 12;

Figure 14 is a B-B view of Figure 13, and is also a schematic structural view of the A2 type pier foundation 8-2 above the ground;

Figure 15 is a C-C view of Figure 13, and is also a schematic structural view of the underside of the A2 type pier foundation 8-2;

Figure 16 is a plan view of the A3 type pier foundation 8-3, the lower part of the ground is indicated by a broken line;

Figure 17 is a view taken along the line A in Figure 16;

Figure 18 is a B-B view of Figure 17, and is also a schematic view of the A3 type pier foundation 8-3 above the ground;

Figure 19 is a C-C view of Figure 17, and is also a schematic structural view of the A3 type pier foundation 8-3 below the ground;

Figure 20 is a plan view of the A4 type pier foundation 8-4, the lower part of which is indicated by a broken line;

Figure 21 is a view taken along line A of Figure 20;

Figure 22 is a B-B view of Figure 21, and is also a schematic structural view of the A4 type pier foundation 8-4 above the ground;

Figure 23 is a plan view of the B1 type pier foundation 9-1, and is also a structural schematic view of the B1 type pier foundation 9-1 formed by embedding four plates;

Figure 24 is a view in the direction of arrow A of Figure 23, and is also a structural schematic view of each of the plates constituting the B1 type pier foundation 9-1 in the set order with the chain cutter 3 at the bottom thereof;

Figure 25 is a B-direction view of Figure 23, and is also a schematic structural view of a vertical geotechnical conveying device 7-2 composed of a chain cutter 3 and a side cover 1-3;

Figure 26 is a C-C view of Figure 23, which is also a structural schematic view of the bottom end opening of the B1 type pier foundation 9-1, and the concrete capping at the ground height position increases the carrying capacity;

Figure 27 is a schematic view showing the structure of the B2 type pier foundation 9-2, which is a structural view of the sprocket 6 and the chain cutter 3 of the chain excavating device 2, and also the B2 type pier foundation 9-2 is completely sunk together with the chain cutter 3 at the bottom. Schematic diagram of the time, the section below the ground of the B2 type pier foundation is consistent with the cross-sectional shape of the above ground part, that is, the pier section is the same as the foundation section;

Figure 28 is a view in the direction of arrow A of Figure 27, and is also a schematic view of the bridge on the top of the B2 type pier foundation 9-2. The B2 type pier foundation 9-2 is internally welded and sealed at the ground height position to increase the axial load carrying capacity;

Figure 29 is a B-B view of Figure 28;

Figure 30 is a schematic view showing the structure of the B3 type pier foundation 9-3. The structure below the ground of the B3 type pier foundation is different from the structure above the ground, that is, the pier section is different from the foundation section;

Figure 31 is a view taken along line A-A of Figure 30;

Figure 32 is a schematic structural view of a B4 type pier foundation 9-4;

Figure 33 is a view taken along line A in Figure 32;

Figure 34 is a B-B view of Figure 33;

Figure 35 is a schematic view of the structure of the B5 type pier foundation 9-5. The B5 type pier foundation is mainly used for the higher main pier foundation. The four pier foundations share one foundation, and each pier foundation has a construction channel reserved for the lower foundation. The bottom cap is reinforced to increase the bearing capacity of the pier foundation;

Figure 36 is a view taken along the line A in Figure 35;

37 is a B-B view of FIG. 35, and is a structural schematic view of the reserved construction channel inside the pier foundation entering the lower foundation for bottom capping reinforcement, and increasing the bearing capacity of the pier foundation;

38 is a schematic structural view of a C-type pier foundation 10, and the C-type pier foundation 10 mainly includes a bottom foundation 10-1, a immersed pipe 10-2, and a connecting beam 10-3, which is suitable for deep water;

Figure 39 is a view taken along line A-A of Figure 38;

Figure 40 is a B-B view of Figure 38;

Figure 41 is a partial enlarged view of I of Figure 38;

Figure 42 is a plan view of the caisson foundation 11;

Figure 43 is a view taken along line A-A of Figure 42;

Figure 44 is a structural schematic view of the bottom rail and the side rail of the pier foundation 1, the type of the rail includes five kinds of a, b, c1, c2 and d, wherein a is a flat type, b is a convex type, and c is a concave type;

Figure 45 is a schematic view showing the structure of the d-shaped rail and the chain cutter of the pier foundation 1;

Fig. 46 is a structural schematic view showing that d is a longitudinally multi-row staggered tapered track.

1 in the figure is the pier foundation with the excavating device at the bottom; 1-1 is the track running the chain cutter 3 at the bottom of the pier foundation 1; 1-2 is the track running the chain cutter 3 on the side of the pier foundation 1; 1-3 is the bottom belt a side cover of the edge of the pier foundation 1; 2 is a chain excavation device composed of a chain cutter 3, a driving device 4, a tensioning device 5, a sprocket 6, etc.; 3 is a chain cutter constituting the chain excavating device 2; -1 is the chain constituting the chain cutter 3, including the crawler, the rope and the flexible belt; 3-1-1 is the A ten-byte which constitutes the ten-byte of the chain; 3-1-2 is the B-cross which constitutes the ten-byte of the chain Section 3-1B is a steel cable constituting the chain cutter 3; 3-2 is a cutter for excavating the rock soil fixed on the chain 3-1; 3-2B is a cutter for excavating the rock soil fixed on the steel cable 3-1B 4 is the driving device of the chain 3-1; 5 is the tensioning device of the chain 3-1; 6 is the sprocket running the chain 3-1; 7 is the geotechnical conveying machine; 7-1 is the chain horizontal geotechnical conveying 7-2 is a chain vertical geotechnical conveyor; 8 is a type A pier foundation; 8-1 is an A1 pier foundation; 8-2 is an A2 pier foundation; 8-3 is an A3 pier foundation; 8- 4 is the A4 type pier foundation; 9 is the B type pier foundation; 9-1 is the B1 type pier foundation; 9 -2 is the B2 type pier foundation; 9-3 is the B3 type pier foundation; 9-4 is the B4 type pier foundation; 9-5 is the B5 type pier foundation; 10 is the C type pier foundation; 10-1 is the C type pier foundation 10 bottom base; 10-2 is the immersed tube of the C-type pier foundation 10; 10-3 is the connecting beam of the C-type pier foundation 10; 11 is the caisson foundation; B-1 is the bottom track in the B method; B -2 is the intermediate frame in the B method; B-3 is the upper frame in the B method; B-4 is the pouring template in the B method.

detailed description

The bottom of the foundation of the pier is provided with a chain knife running track. During the construction, a chain cutter for excavating rock and earth is installed on the track, the chain knife is composed of a chain and a cutter fixed on the chain; the chain excavating device is mainly composed of a chain cutter and a transmission. The device is composed of a device such as a sprocket and a driving device; the driving device drives the chain knife, the chain knife runs along the track, the cutter at the bottom of the pier foundation excavates the rock and soil, and the chain knife that runs vertically upwards will excavate the rock and soil Sent to the top, the chain knife at the bottom of the pier foundation and the foundation of the pier are lowered together.

The chain cutter replaces the cutter on the chain on the work platform or in the passage to adapt to different geological conditions at different depths.

The chain cutter is a multi-row chain cutter in the width direction, and the multi-row chain cutter performs simultaneous excavation or separate excavation as needed.

The construction method of the pier foundation is a prefabrication method, which is divided into the following steps:

1) Blocking or integral prefabricated pier foundations at the workshop;

The construction method of the pier foundation is the cast-in-place method, and the concrete except the bottom of the pier foundation is poured in the fixed formwork on the site, and the fixed formwork does not move during the construction, and the bottom of the pier foundation is poured with the bottom of the earth and earth. The chain excavation device is installed on the frame, the frame is composed of the intermediate frame and the upper frame, the bottom of the intermediate frame is connected with the bottom of the pier foundation, the top of the intermediate frame is connected with the upper frame, and the middle frame is installed. The track with the chain cutter running, the middle frame is the integral part of the foundation steel cage of the pier, and the chain cutter and the closed cavity of the intermediate frame from the bottom up constitute a chain-type vertical soil conveyor, with the bottom of the foundation of the pier foundation Sink, the intermediate device also sinks synchronously; the upper frame is fixed on the work platform or fixed on the top of the intermediate frame, the upper frame is equipped with a chain drive device and a tensioning device, and the chain at the bottom of the pier foundation passes through the intermediate frame and the upper portion The driving device of the frame and the tensioning device are connected; the cast-in method is divided into the following steps:

1) Clean up the site and build an operating platform;

3) Assembling the intermediate frame, the upper frame and the pouring formwork;

5) Making a steel cage and pouring concrete in the formwork;

The pier foundation is the A-type pier foundation.

The pier foundation is a B-type pier foundation.

The bridge pier foundation C-type pier foundation.

The pier foundation is the sinking foundation.

The chain constituting the chain cutter is a generalized chain including a crawler belt, a rope and a flexible belt.

The technical solution of the present invention is further described below with reference to the accompanying drawings:

As shown in FIGS. 1 to 5, the piers are provided with rails 1-1 and 1-2 in which the chain excavating device 2 is operated, and the chain excavating device 2 is composed of a chain cutter 3, a driving device 4, a tensioning device 5, and a sprocket. 6 composition, the chain knife 3 is composed of a chain 3-1 and a cutter 3-2 fixed on the chain; the driving device 4 drives the chain 3-1 during construction, and the chain 3-1 drives the cutter 3-2 to run along the track, the pier foundation The bottom tool 3-2 excavates the rock and soil. The horizontal chain cutter 3-2 at the bottom of the pier foundation is also a horizontal geotechnical conveyor 7-1. The chain knife 3-2 and the side cover 1-3 moving upward from the bottom form a chain. Vertical vertical earth and soil conveyor 7-2, the rock excavated from the bottom of the pier foundation reaches the top through the horizontal geotechnical conveyor 7-1 to the chain vertical geotechnical conveyor 7-2, and the bottom chain knife 3 and the pier foundation 1 together Synchronously descending, after falling to the set depth, the chain 3-1 is disconnected, and the chain cutter 3 is all pumped up and recovered by the driving device, and then grouted.

As shown in Figure 6, the pier foundation is divided into the following steps by the A method prefabrication method:

1) Prefabricated pier foundation 1 in the workshop, transported to the site to assemble the pier foundation 1 and clamped, and install the chain knife 3 on the track at the bottom, install the chain drive device 4, etc., and connect the chain with the excavating knife 3 3-1, as shown in A of the figure;

2) Drive the chain 3-1, the chain knife excavates the rock at the bottom, and the rock-to-earth conveying device 7 is sent to the upper part, and the foundation of the pier is lowered, as shown in B in the figure;

3) After descending to a certain depth, the prefabricated parts of the pier foundation 1 can be assembled on the ground, or they can be assembled while sinking, as shown in C in the figure;

4) Grout after falling to the design depth, or remove the chain cutter 3 and then grout, as shown in D of the figure.

As shown in Figure 7, the pier foundation is divided into the following steps by the B method:

1) Clean up the site and build an operating platform;

2) Assembling the bottom rail B-1 and the pouring formwork B-4, that is, the bottom clamp of the pier foundation 1, and installing the chain cutter 3 on the rail at the bottom thereof;

3) Assembling the intermediate frame B-2 and the upper frame B-3;

4) The chain drive device 4, the tensioning device 5, the bottom rail B-1, the intermediate frame B-2, the upper frame B-3 chain 3-1 are connected to form a chain excavation device 2;

5) Making a steel cage, welding the intermediate frame B-2 with the steel cage, and the intermediate frame B-2 is also a component of the pouring template;

6) pouring concrete in template B-4;

7) Drive the chain 3-1, the chain cutter 3 excavates the rock at the bottom, and transports the excavated rock and soil to the upper part through the intermediate device B-2, and the pier foundation 1 descends accordingly;

8) With the excavation of the bottom of the pier foundation 1, the side of the pier foundation in the form B-4 is lowered;

9) Drop to the design depth to remove the chain cutter 3 after grouting;

10) Remove the upper frame and the intermediate device above the pier foundation 1 and remove the pouring formwork;

The above description of the pier 1 has been made, and the various structures of the pier below can be similarly constructed.

As shown in Figure 8 to Figure 11, the pier foundation 1 is the A1 type pier foundation 8-1, the lower part of the ground is I-shaped, and the ground above is a figure. The cross-sectional area of the pier below the ground is larger than the cross-section area of the pier above the ground. Strong ability, small footprint on the ground above the pier.

As shown in Fig. 12 to Fig. 15, the pier foundation 1 is the A2 type pier foundation 8-2, the lower part of the ground is I-shaped, and the ground above is one-line on each side. The cross-sectional area of the pier below the ground is larger than the cross-section area of the pier above the ground. Large, strong carrying capacity, the pier above the ground is in a shape on both sides.

As shown in Fig. 16 to Fig. 19, the pier foundation 1 is the A3 type pier foundation 8-3, the lower part of the ground is I-shaped, and the ground above is a cross type on each side. The cross-section of the pier above the ground is large and the rigidity is good. A bridge with a higher pier above the ground.

As shown in Fig. 20 to Fig. 22, the pier foundation 1 is the A4 type pier foundation 8-4, the lower part of the ground is I-shaped, and the ground above is a cylindrical type on both sides. The cross-sectional area of the pier below the ground is larger than the cross-section area of the pier above the ground. , carrying capacity is strong.

As shown in Fig. 23 to Fig. 26, the pier foundation 1 is a B1 type pier foundation 9-1, and the lower part of the ground is a well-shaped pier, and the lower end is open, and concrete capping is placed at the surface height to increase the bearing capacity.

As shown in Fig. 27 to Fig. 29, the pier foundation 1 is a B2 type pier foundation 9-2, and the cross-sectional shape of the pier above the ground is the same as that of the pier below the ground, and both are well-shaped, and the lower end of the pier is open. Pouring concrete caps at height locations increases load carrying capacity.

As shown in Fig. 30 to Fig. 31, the pier foundation 1 is the B3 type pier foundation 9-3. The cross-sectional shape of the pier above the ground is different from the cross section of the pier below the ground. The ground below is the well type, and the ground above is hollow. rectangle.

As shown in Fig. 32 to Fig. 34, the pier foundation 1 is a B4 type pier foundation 9-4, the lower part of the ground is a well type, and the above part of the ground has a cross shape at each of the four corners, and the pier above the ground has good rigidity. Strong carrying capacity, suitable for the main pier.

As shown in Fig. 35 to Fig. 37, the pier foundation 1 is the B5 type pier foundation 9-5, the lower part of the ground is the well-shaped pier foundation, and the four piers share one foundation, and each pier has a construction channel to enter the lower foundation. The bottom capping reinforcement is carried out to increase the bearing capacity of the pier, which is suitable for the main pier of the cable bridge.

As shown in Fig. 38 to Fig. 41, the pier foundation 1 is a C-type pier foundation 10, which is suitable for deep water area. The immersed pipe 10-2 and the connecting beam 10-3 form a dry bottom construction environment, and the pier is constructed at the bottom of the immersed pipe. Foundation 10-1, pier foundation 10-1 is a well-shaped pier, with a chain knife at the bottom, and the chain cutter excavates the rock-soil pier and the chain knife to descend. After reaching the set depth, the roof is reinforced, so that the pier foundation 10-1 and the immersed pipe The 10-2 and the connecting beam 10-3 constitute a deep water C-type pier foundation 10.

As shown in Fig. 42 and Fig. 43, the pier foundation 1 is a caisson foundation, which is suitable for deep water areas and large pier foundations.

Claims

A pier foundation, characterized in that the bottom of the pier foundation is provided with a chain knife running track, and a chain cutter for excavating rock and earth is installed on the track during construction, the chain knife is composed of a chain and a cutter fixed on the chain; the chain excavating device It is mainly composed of a chain knife and a transmission device. The transmission device is mainly composed of a sprocket and a driving device. The driving device drives the chain knife, the chain knife runs along the track, the cutter at the bottom of the pier foundation excavates the rock and soil, and the chain knife runs vertically upward. The excavated rock and soil is sent to the top, and the chain cutter and the pier foundation at the bottom of the pier foundation are lowered together.
A pier foundation according to claim 1 wherein said chain cutter replaces the tool on the chain on the work platform or in the passage to accommodate different geological conditions at different depths.
A pier foundation according to claim 1, wherein said chain cutter is a plurality of rows of chain cutters in the width direction, and the plurality of rows of chain cutters are simultaneously excavated or separately excavated as needed.
The method for constructing a pier foundation according to claim 1, wherein the construction method of the pier foundation is a prefabrication method, and the following steps are as follows:

1) Blocking or integral prefabricated pier foundations at the workshop;

2) transport to the site to assemble the foundation of the pier and clamp it, and install the chain knife on the track at the bottom;

3) Install a chain drive and other devices to connect the chain with the cutter installed;

4) drive the chain, the chain knife excavates the rock at the bottom of the foundation of the pier, and the chain cutter that runs vertically upwards is brought to the top, and the base chain and the pier foundation at the bottom are lowered;

5) Grout after falling to the design depth, or remove the chain knife and then grout.
The method for constructing a pier foundation according to claim 1, wherein the construction method of the pier foundation is a cast-in-place method, and the concrete except the bottom of the pier foundation is poured in a fixed form on the site, and the template is fixed during construction. Do not move, as the bottom of the bottom earth excavation pier foundation sinks while sinking; the chain excavation device is installed on the frame, the frame consists of the intermediate frame and the upper frame, the bottom of the intermediate frame and the bottom of the pier foundation Connected, the top of the intermediate frame is connected to the upper frame, and the middle frame is equipped with a chain knife running track. The middle frame is a component of the pier base reinforcement cage, and the chain knife running from the bottom upward and the closed cavity of the intermediate frame Forming a chain-type vertical geotechnical conveyor, the intermediate device is simultaneously sunk as the bottom of the pier foundation sinks; the upper frame is fixed on the work platform or fixed on the top of the intermediate frame, and the upper frame is mounted with a chain drive The device and the tensioning device, the chain at the bottom of the pier foundation is connected to the driving device and the tensioning device of the upper frame through the intermediate frame; the cast-in method is divided into the following steps:

1) Clean up the site and build an operating platform;

2) Assembling the bottom of the foundation of the pier and installing a chain knife on the track at the bottom;

3) Assembling the intermediate frame, the upper frame and the pouring formwork;

4) Install the chain drive device and the tensioning device, and connect the chain cutters at the bottom of the pier foundation, the intermediate frame and the upper frame to form a chain excavation device;

5) Making a steel cage and pouring concrete in the formwork;

6) Drive the chain, the chain drives the tool to run along the track, the chain knife at the bottom of the pier foundation excavates the rock and soil, and the chain knife that runs vertically upwards transports the excavated rock and soil to the upper part, and the pier foundation decreases accordingly;

7) As the bottom of the foundation of the pier is lowered, the foundation of the pier in the formwork is lowered while pouring;

8) Drop to the design depth After the chain cutter is removed, the grout is removed and the pouring formwork is removed.
A pier foundation according to claim 1, wherein said pier foundation is a type A pier foundation.
A pier foundation according to claim 1, wherein said pier foundation is a B-type pier foundation.
A pier foundation according to claim 1 wherein said pier foundation is a C-type pier foundation.
A pier foundation according to claim 1 wherein said pier foundation is a sinking foundation.
A pier foundation according to claim 1 wherein said chain forming the chain cutter is a generalized chain comprising a track, a rope and a flexible.